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Sewage Works Upgrades

Crossness Sewage Treatment Works

We are carrying out a £220m upgrade at Crossness Sewage Treatment Works.

Work at Crossness will help prevent sewage entering the River Thames during heavy rainfall.

The improvements will enable the site to treat 44 per cent more sewage than it does now, significantly reducing the amount of storm sewage that overflows into the River Thames during heavy rainfall when the site becomes overloaded.

The project will include the installation of renewable energy sources on site which will include a wind turbine and thermal hydrolysis plant (THP).

The THP is currently under construction. This industrial-scale ‘pressure cooker’ will heat sludge, the leftover solids from wastewater treatment, to around 160 °C, in order to produce up to 50 per cent more biogas, which is then burnt to create heat to generate renewable energy.

By the end of this year, the wind turbine will be installed and in the right weather conditions the 78.5 metre-high turbine will provide enough energy to power 1,300 homes.

The upgrade at Crossness will also see new odour-controlled treatment processes and environmental enhancements.

Enhancement work has also been carried out at Crossness Nature Reserve and the Southern Marshes – which included creating a suitable habitat for water voles and birds.

Crossness currently serves two million Londoners. On completion of the upgrade next year, the site’s treatment capacity will be boosted by 44 per cent. This will significantly reduce the amount of storm sewage that overflows into the tidal River Thames after heavy rainfall.